?Parasitism? refers to the successful invasion of and survival within a host by a microbe. The outcome of microbial infection is influenced by both host defense and microbial virulence factors. Advances in immunology, molecular biology, cell biology and host/microbial genetics have illuminated common themes governing the outcome of microbe-initiated diseases. Lessons learned from one infectious disease can enhance our understanding of diseases caused by another. This Mechanisms of Parasitism training program represents a union between the fields of parasitology, bacterial pathogenesis and immunology into a single program. Its goal is to enhance collaborative research and training among laboratories at the University of Iowa specializing in these disciplines, and in the process provide a rich environment for the development of trainees. Since its beginning four years ago, the Mechanisms in Parasitism program has funded 15 trainees, initiated a Research Retreat and Journal Club, sponsored outside speakers, and created a ?T32 room? to provide trainees with computerized support. During the coming grant period we additionally propose to expand the Journal club to a Parasitism Research Meeting, add faculty from the new and productive Inflammation Group, and initiate a ?target recruiting? approach for postdoctoral fellows. We propose to maintain our postdoctoral fellow positions at 3 but expand from 3 to 4 predoctoral trainee positions due to the number of high quality candidates we have had to turn down for funding. This program has provided a productive environment where there is exchange of creative ideas between faculty and trainees working on different aspects of microbial infection. We propose in this application to enhance the program and to further enrich our training environment during an additional five-year funding period.